Microwave Spectrum and Molecular Conformation of δ-Valerolactam

Slow Photoelectron Spectroscopy of δ‐Valerolactam and Its Dimer

“…Indeed, the C 1 -N 2 , C 1 -C 11 , C 1 -O 3 distances are longer and these angles are varying by~108 upon ionization of this molecule. For the neutral molecule, our geometrical parameters compare quite well with those determined through the microwave study of Kuze et al [6] and those computed recently by Pandey et al [9] We display in Table 3 the harmonic and anharmonic wavenumbers (in cm À1 ) of the 42 vibrational modes of d-valerolactam + in its electronic ground state. These data are computed at the PBE0/aug-ccpVDZ level and using the standard options as implemented in Gaussian.…”

“…Later on, the equilibrium molec-ular conformation was reinvestigated and precisely determined after analysis of the microwave spectrum of d-valerolactam in the gas phase. [6] A chair form is definitely established for this lactam, in accordance with modified neglect of diatomic overlap (MNDO) semi-empirical and ab initio theoretical results at the HF/3-21G, MP2/6-31G(d,p), DFT/B3PW91/6-311 + + G** and MP2/6-311 + + G** levels of theory. [6][7][8][9] The molecular structure of the d-valerolactam 2 dimer was characterized using IR, NMR and Raman spectroscopies and theoretical ab initio treatments.…”

“…[6] A chair form is definitely established for this lactam, in accordance with modified neglect of diatomic overlap (MNDO) semi-empirical and ab initio theoretical results at the HF/3-21G, MP2/6-31G(d,p), DFT/B3PW91/6-311 + + G** and MP2/6-311 + + G** levels of theory. [6][7][8][9] The molecular structure of the d-valerolactam 2 dimer was characterized using IR, NMR and Raman spectroscopies and theoretical ab initio treatments. [10][11][12][13][14][15][16] These works proved the C 2 symmetry of the cyclic hydrogen-bonded dimer (denoted in…”

“…For the neutral molecule, our geometrical parameters compare quite well with those determined through the microwave study of Kuze et al [6] and those computed recently by Pandey et al [9] We display in Table 3 the harmonic and anharmonic wavenumbers (in cm…”

Chirped-pulsed FTMW spectra of valeric acid, 5-aminovaleric acid, and δ-valerolactam: A study of amino acid mimics in the gas phase

“…But a unique fit of the observed spectrum to a rigid-rotor Hamiltonian was obtained using the predicted rotational constants of the condensation product d-valerolactam (DVL, Scheme 2). The parameters (including N-14 coupling constants) obtained from this fit are listed in Table 2 and show excellent agreement with both theory and the rotational constants previously measured by Kuze, et al [18] Subsequent experiments on authentic samples of DVL were performed on the broadband spectrometer at UVa. Deep signal averaging on this instrument made possible the detection of singly substituted 13 C and 15 N species in natural abundance.…”